• Environmental Mutagens and Carcinogens
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• v.26 no.2
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• pp.48-52
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• 2006

Our investigation of the seaweed extracts, Ulva lactuca. The biological activities antioxidant, antimicrobial activity, antifungal and haemolytic activity of ethy-ether and ethyl-acetate extracts from the seaweed, Ulva lactuca were investigated. They were separately extracted using ethyl-ether and ethyl-acetate from dried samples at room temperature and freeze dried. Seaweed extracts were found to cause significant free radical scavenging effects on DPPH (1,1-diphenyl-2-picrylhydrazyl). Seaweed extracts had not significant haemolytic activity against human erythrocyte. This extracts exhibited in vitro broad-spectrum antimicrobial activity of gram-negative, gram-positive bacteria and without antifungal activity.

• Journal of Ginseng Research
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• v.35 no.1
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• pp.60-68
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• 2011

The chemical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity changes of ginsenoside $Rb_1$-glycine and ginsenoside $Rg_1$-glycine mixtures by Maillard reaction were investigated to identify the role of Maillard reaction in the increased antioxidant activity of ginseng by heat-processing. The DPPH radical scavenging activity of $Rg_1$-glycine mixture was more strongly increased by heat-processing than that of $Rb_1$-glycine mixture. From the analyses of ginsenosides, $Rb_1$ was gradually changed into 20(S)-$Rg_3$, 20(R)-$Rg_3$, $Rk_1$ and $Rg_5$ by heat-processing. $Rg_1$ was gradually changed into 20(S)-$Rh_1$, 20(R)-$Rh_1$, $Rk_3$ and $Rh_4$ by heat-processing. However, the generation of these less-polar ginsenosides was not related to the increased DPPH radical scavenging activity of $Rb_1$-glycine and $Rg_1$-glycine mixtures because their DPPH radical scavenging activities were already significantly increased when dried at $50^{\circ}C$, which temperature induce no structural changes of ginsenosides. In the comparison of browning compound levels of $Rg_1$-glycine and $Rb_1$-glycine mixtures, the extents of Maillard reaction were positively correlated with their increased free radical scavenging activities. Based on the chemical and DPPH radical scavenging activity changes of $Rg_1$-glycine and $Rb_1$-glycine mixtures by heat-processing, we clearly identified that the increased free radical scavenging activity of ginsenoside is mediated by the Maillard reaction between sugar moiety of ginsenoside and amino acid.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.116-122
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• 2007

Four compounds with antioxidant activity were isolated from the MeOH extract of peanut shells (pod) and identified as 5,7-dihydroxychromone (1), eriodictyol (2), 3',4',7-trihydroxyflavanone (3), and luteolin (4) by electron impact-mass spectrometry (EI-MS) and nuclear magnetic resonance (NMR) analyses. The relationship between antioxidant activity and chemical structure of the isolated compounds with their analogues [(-)-epicatechin, quercetin, taxifolin] was examined by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and using the 2-deoxy-D-ribose degradation system. The order of antioxidant activity on the basis of DPPH radical-scavenging was quercetin = (-)-epicatechin (6.0 molecules) > taxifolin (4,5 molecules) > 4 (luteolin; 4.0 molecules) > 2 (eriodictyol; 2.5 molecules) > 3 (3',4',7-trihydroxy-flavanone; 2.0 molecules) > 1 (5,7-dihydroxychromone; 0.5 molecules). On the other hand, using the 2-deoxy-D-ribose degradation system, the order of antioxidant activity was quercetin > 4 >> (-)-epicatechin ${\geq}\;2\;{\geq}$ taxifolin > 3 > 1. These compounds from peanut shells may provide defensive measures against oxidative stress and insects in the soil.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.159-167
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• 2008

This study was carried out to investigate the potential promise of Chamaecyparis obtusa oil as a natural antioxidant. C. obtusa oil and its fractions were subjected to screening for their antioxidant activities by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and ammonium thiocyanate method. In the first case, $IC_{50}$ value of the C. obtusa oil was determined as $40{\mu}{\ell}/m{\ell}$. At $0.5{\mu}{\ell}/m{\ell}$ concentration level, free radical scavenging effect of fraction G determined as 66.94% was the highest among the fractions of C. obtusa oil. In the ammonium thiocyanate method, essential oil of C. obtusa and its fraction C, D, and E showed activities of 72.0%, 71.2%, 71.9% and 71.1%, respectively. Fraction G, most active fraction, was mainly consisted of $\alpha$-terpineol, elemol, widdrol and $\alpha$-cadinol.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1299-1304
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• 2008

The potential antioxidant activities of different fractions from a 70% methanolic (MeOH) extract of Sonchus oleraceus were assayed in vitro. All of the fractions exception of n-hexane showed a strong antioxidant activity, especially the ethyl acetate (EtOAc) fraction, which showed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity ($IC_{50}=19.25{\mu}g/mL$). The results of hydroxyl radical scavenging activity and a reducing power assay showed concentration dependence, the EtOAc fraction demonstrating a better result than the other fractions at the same concentration in the studies. Additionally, the fractions' total phenolic (TP) contents was measured, phenolic compounds such as tannic acid, p-coumatric acid, quercetin, epicathchin, and kaempferol being detected by high performance liquid chromatography (HPLC). Meanwhile, a regression analysis revealed a moderate-to-high correlation coefficient between the antiradical activity and the TP contents, suggesting that fractions obtained from the 70% MeOH extract of S. oleraceus are of potential use as sources of antioxidant material.

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.865-872
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• 2002

In the course of the investigations of natural antioxidants, we examined the antioxidant activities of the methanol (MeOH) extracts of some selected Prunus species, including P. buergeriana, P. davidiana, P padus, P. pendula for. ascendens, P. sargentii, P. serrulata var. spontanea and P. yedoensis by three methods as represented by the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, total ROS (reactive oxygen species) and the peroxynitrite ($ONOO^-$) scavenging activity tests. We also evaluated the activities of the organic solvent-soluble fractions, including the dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc), n-butanol (n-BuOH) fractions and the water ($H_2O$) layer of P. serrulata var. spontanea leaves. By means of bioassay-directed fractionation, we isolated eleven known flavonoids (1-11) from the EtOAc soluble fraction of the MeOH extract of the Prunus serrulata var. spontanea leaves, exhibiting strong antioxidant activity and characterized as prunetin (1), genistein (2), quercetin (3), prunetin $4'-O-{\beta}-glucopyranoside$ (4), kaempferol $3-O-{\alpha}-arabinofuranoside$ (5), prunetin $5-O-{\beta}-glucopyranoside$ (6), kaempferol $3-O-{\beta}-xylopyranoside$ (7), genistin (8), kaempferol $3-O-{\beta}-glucopyranoside$ (9), quercetin $3-O-{\beta}-glucopyranoside$ (10) and kaempferol $3-O-{\beta}-xylopyranosyl-(1{\rightarrow}2)-{\beta}-glucopyranoside$ (11). Compounds 3 and 10 showed good activities in all tested model systems. Compounds 2 and 8 showed scavenging activities in the DPPH and $ONOO^-$ tests, while compounds 5, 7, 9 and 11 were active in the $ONOO^-$ and ROS tests. On the other hand, compounds 1, 4 and 6 did not show any activities in the tested model systems.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.361-364
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• 2003

Acanthopanax species (Araliaceae) has been traditionally used as tonic, analgesic, stimulant of immune system, and replenishment of body function. The antioxidant activities of leaf and root bark of Acanthopanax species were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and thiobarbituric acid reactive substances (TBARS) assay and relative electrophoretic mobility (REM) on human plasma low density lipoproteins (LDL). Acanthopanax divaricatus var. albeofructus and Acanthopanax for. nambunensis showed potent antioxidant activities.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.40-44
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• 2003

This study was carried out to investigate the antioxidant activities of domestic trees grown in Korea. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity method, the methanolic extracts of 23 species were screened in order to search for natural antioxidants. Among these species, Acer ginnala, Cotinus coggygria, Acanthopanax koreanum, Thea sinensis and Pinus densiflora showed stronger antioxidative activity comparing with reference compound, ascorbic acid.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.290-293
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• 2007

Cassumunar ginger (Zingiber montanum Roxb.) was grown in the experimental field at the Department of Horticulture, Kasetsart University, Thailand. The antioxidant activity and volatile oil content of rhizomes of varying age were measured. Antioxidant activity as determined using the DPPH (diphenyl-2-picrylhydrazyl) method differed significantly between samples of different ages. Antioxidant activity and rhizome age were positively correlated, with 22-month old rhizomes showing the highest radical scavenging activity (79.19%). Volatile oil was obtained by steam distillation of fresh rhizomes. The extraction yield of volatile oil was highest in l6-month old rhizomes (13.02 mL/kg). GC-FID data indicated the presence of three major compounds, sabinene, terpinen-4-ol and (E)-1-(3',4'-dimethylphenyl) butadiene (DMPBD), however none of the major components were correlated with the age of rhizome.

• The Korea Journal of Herbology
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• v.29 no.6
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• pp.111-116
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• 2014

Objectives : The purpose of this study was to estimate the antioxidant activity of water extract of Cnidii Fructus (CF) and Torilis Fructus (TF) in Leydig cells. Methods : Free radical scavenging activity of CF and TF against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was determined spectrophotometrically. We investigated the effect of CF and TF in Leydig cells by MTT assay. The protective effects of CF and TF against hydrogen peroxide-induced oxidative stress in Leydig cells. Superoxide dismutase (SOD), and catalase activity assays were performed in Leydig cells. Results : The results showed that CF scavenged DPPH radical in a dose-dependent manner by up to 81.2%, TF scavenged DPPH radical in a dose-dependent manner by up to 63.8%. CF showed cell viability as 121.0, 132.7, 126.6% in 5, 10, $100{\mu}g/ml$ concentrations. TF showed cell viability as 127.5, 111.8% in 5, $100{\mu}g/ml$ concentraions, respectively. The hydrogen peroxide-induced cytotoxicity of Leydig cells were protected to 86.3% by CF at concentration of $10{\mu}g/ml$ and protected to 83.5% by TF at concentration of $100{\mu}g/ml$. Both CF and TF at all concentrations, SOD activity was not significantly changed. Catalase activity was significantly increased at 10, $100{\mu}g/ml$ concentrations of CF, respectively. TF's catalase activity showed no significant difference from that of the control. Conclusions : These results suggest that CF, as an antioxidant, protects Leydig cells in hydrogen peroxide-induced oxidative stress. know that "Kwangjebikeup" played a role in settlement and spreading of foreign knowledge to civilians.